我试图在JTable中显示来自我的字符串数组(创建的方法)的结果 - 但它似乎不工作。JAVA-用SQL中的2d字符串数组填充JTable
代码方法(只粘贴前两个):
package t3.isprojekt.uppg2.dal;
import java.sql.*;
import java.util.*;
public class DAL {
private static String connStr = "jdbc:sqlserver://Localhost:1433;databases=CronusDB;user=root;password=root;";
public static Connection getConn() throws SQLException {
return DriverManager.getConnection(connStr);
}
// ------ Methods for Employee & related tables ------\\
public String[][] getEmpData() throws SQLException {
String getEmp = "SELECT [No_], [First Name], [Last Name], [Address], [City] FROM [CRONUS Sverige AB$Employee];";
Statement stmt = null;
stmt = getConn().createStatement();
ResultSet rset = stmt.executeQuery(getEmp);
ResultSetMetaData rsetMeta = rset.getMetaData();
int colCount = rsetMeta.getColumnCount();
int rowCount = 0;
while (rset.next()) {
rowCount = rset.getRow();
}
String[][] temp = convertRsToArray(rset, rowCount, colCount);
return temp;
}
public String[][] getEmployeeMetaData() throws SQLException {
String empMetaData = "SELECT TABLE_CATALOG, TABLE_NAME, COLUMN_NAME, DATA_TYPE FROM [CronusDB].[INFORMATION_SCHEMA].[COLUMNS]";
Statement stmt = null;
stmt = getConn().createStatement();
ResultSet rset = stmt.executeQuery(empMetaData);
ResultSetMetaData rsetMeta = rset.getMetaData();
int colCount = rsetMeta.getColumnCount();
int rowCount = 0;
while (rset.next()) {
rowCount = rset.getRow();
}
String[][] temp = convertRsToArray(rset, rowCount, colCount);
return temp;
}
GUI类 - 在这里,我不知道如何将模型连接到字符串数组。试图谷歌,但没有恢复到什么,我想实现的任何信息:
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.sql.SQLException;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.border.EmptyBorder;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableModel;
import t3.isprojekt.uppg2.controller.Controller;
import t3.isprojekt.uppg2.dal.DAL;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class View extends JFrame {
private JPanel contentPane;
private Controller ctrl;
private DefaultTableModel tableModel = new DefaultTableModel(new Object[][] { ctrl.getEmployeeData() },
new Object[] { ctrl.getEmpMetaData() });
private JTable table_2;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
View frame = new View();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*
* @throws SQLException
*/
public View() throws SQLException {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);
JTable table = new JTable(tableModel);
table.setBounds(0, 65, 432, 188);
contentPane.add(table_2);
JScrollPane scrollPane = new JScrollPane();
scrollPane.setBounds(0, 247, 432, -175);
contentPane.add(scrollPane);
}
}
是的,这是一个错字,我的坏。但是当我试图在这个语句上运行它时,我得到了NullPointerException: ''private DefaultTableModel tableModel = new DefaultTableModel(new Object [] [] {ctrl.getEmployeeData()}, new Object [] {ctrl.getEmpMetaData()} );” ' – user2868900
那么一个nullpointers意味着你应该调试你的代码。在线上做一个断点,你instanciate你的tableModel和看起来至极参数是null。 –